These days, services of displaying an indoor map on a mobile portable terminal and displaying a route from a present location to a desired location thereon have been suggested. For example, by installing a predetermined application, the present position can be displayed on a map of station premises displayed on a display unit of a mobile portable terminal and a route to a destination such as a toilet can be displayed thereon.
Techniques of calculating a distance between two points in consideration of a route through the use of a route network are also known. For example, a route search in consideration of gateways of facilities can be realized. In this case, a route search can be carried out in which a facility is provided with nodes and links in addition to normal nodes and links and gateways for connecting the inside and the outside of the facility are provided with nodes. Accordingly, in a route search in which a start point is outside the facility and a destination is inside the facility, it is possible to search for a route passing through the optimal gateway by seamlessly using the nodes and links.
In an inquiry method about a space, such as “feeds back an object within a range (target area) of a predetermined distance from a certain spot”, techniques of making an inquiry by designating a target area by the use of simple geometric shapes such as circles, rectangles, and polygons are known. These techniques are directed to, for example, analysis of land prices or criminal occurrence situations in a city. Accordingly, since the scale of a map to be used is relatively wide (at a block level) and the error of a global positioning system (GPS) is large, no particular problem occurs in the above-mentioned designation of a target area using the simple geometric shapes.
For example, Japanese Laid-open Patent Publication No. 2007-248472 is known as a technique according to the related art.
However, in the future, there is a possibility to upgrade route networks even in indoor places. When an indoor route network is provided along with a map, a route distance between spots in indoor places can be calculated. However, when a route distance between points not registered as spots is calculated, the use of a rout network is not realistic.
With the progress in technical development of positioning and the enhancement in precision of position information of a person in an indoor place, indoor maps as well as outdoor maps have been created and the precision of the maps have been enhanced. Accordingly, when it is considered that services in consideration of high-precision position information of a person are provided in a place such as an indoor place in which spatial structures are complicated, designation of a target area using simple shapes as in the related art frequently causes inconvenience.
For example, a service is assumed in which an alarm is rung when someone gets close to a person indoor. At this time, when the closeness is determined using a circular target area, the circle passes through a wall and thus a person present in a neighboring room may be extracted. In this case, an alarm is rung even when no one is present in the present room, and a feeling of wrongness is given to a user, which is erroneous determination. In this way, the area designating method in a spatial search simply allows only the area designation using fixed shapes such as circles, rectangles, and polygons, and an inquiry method about a space corresponding to high-precision position detection and high-precision maps is not provided yet.